Amiss
by Pheonix500
Summary: Something is very wrong with Casey Jones. Can his friends figure it out before its too late? Not TTB. One shot, written for the April Writer Nexus challenge on Deviant Art, although I might submit another story for that contest.
**Amiss**

 _2016_

 **Disclaimer: I have no claims on anything TMNT, created by Eastman and Laird and currently owned by Viacom (to the best of my knowledge). This is just for fun and I have no intention to profit from this. Which is why I am happily turning it loose onto the internet. If anyone wants to use this story or my take on any of these proprietary characters for their own original work, alternate version of events, prequel, sequel, one shots or art, have at it and have fun. I really would like to see what comes of it.**

 **Note: This story, inspired by really vivid image of Casey's eyes in this story, was languishing in my idea queue until a writer nexus prompt brought it to life. That said, I think I'm actually going to submit a different story for that battle. Even so, I don't regret writing this. It was a good chance to practice some horror and suspense.**

"These guys just can't take a hint." Raph peered down from the roof of the warehouse.

Casey stepped up beside him, grinning underneath his mask. "No point in being subtle then."

His friend snorted in agreement, throwing a smoke bomb into the crowd of Kraang below before leaping from the roof onto the top of the semi-trailer beside them and diving into the cluster, sais at the ready.

"Show off. Hogging all the fun." Casey muttered as he pulled a coil of rope from his utility bag and looped the pre-tied end around a steel exhaust pipe coming out of the roof.

He could have covered the distance with his skates and a ramp, though stopping before skidding off the far side of the trailer would have been a problem. Stupid mutant super abilities. He'd never admit it out loud, but he was just a little bit jealous. Maybe Donnie could hook him up with some kind of robo-exoskeleton. All he'd have to do was mention it. Talking to Don was like igniting the fuse of a bomb. Once lit, D just couldn't help himself.

Tossing the rest of the rope over the side he slid down, feeling the heat of the friction even through his thick, leather gloves. Landing with a loud thud, he scowled to see Raph, sliding the decapitated skull of the last Kraang-droid off his sai in the clearing smoke.

Raph smirked. "You snooze, you lose."

Then the warehouse doors burst open revealing a secondary battalion of Kraang and Casey laughed, drawing a hockey stick and dropping some pucks. "Now we're talking. Goongala!"

Raph charged in as he launched a barrage of projectiles into their approaching enemies. Once they were too close for ranged attacks, he activated his skates and traded his wooden stick for an aluminum bat, smashing apart the joints, the Kraang-droid's weakest points as he darted between their laser blasts.

It was sheer chance that he turned back in time to see a Kraang-droid finish loading up the last crate into the trailer and pull the rear door down. Raph must have damaged the metal crate in his initial assault because its contents had leaked all over the droid's shoulders and upper arms while finishing up the task. Mutagen. Don would be happy to get a fresh supply to work with.

He skated after the droid as it rushed to the cab, hoping to escape with the goods while Casey and his shelled side-kick were distracted. Not gonna happen.

Catching up fast, he knocked the Kraang's head out of the park with his bat, but the little pink blob still had some control for the moment and spun the droid around, clamping its hands firmly on Casey's shoulders, pinning him against the trailer. Then it shorted out, freezing them in that awkward tableau.

Casey couldn't pull free and was at a terrible angle for kicking. Without its bot, the Kraang was just a lump of squishy, pink flesh. Or so he thought.

It thrust out of its compartment and flew at his face, entangling its tentacles around his throat while it gnawed at his mask. He could hear its pointy teeth scraping against his facial armor as he reached up with his less padded hand to try plucking the little freak off his face. Its tentacles tightened around his throat and he realized he couldn't draw in anymore air.

Hoping this wasn't going to be a terrible mistake, he lifted his other hand and jammed the potato-masher Taser into the Kraang, flooding its little body with a squeal-inducing jolt that left it limp and motionless. Good thing the little guy worked like insulation or he might have some nasty electrical burns on his face that would take some serious explaining at home and school.

Doing his best to disregard the smell, he easily pulled the Kraang off of him and tossed it aside, ignoring its semi-conscious screech as it landed. Now to figure out how to get out of this tin-grapple before Raph found him and fell over laughing.

He looked up at the frozen, headless droid looming over him and came to terrifying realization. The mutagen on its shoulders was sliding off. Right towards him.

* * *

Adrenaline pumping, Raph scanned the area, disappointed to find there was nothing left.

"Aaaaahhhhhh!" Casey's scream pierced the night and he spun back toward the truck trailer.

What had that bonehead gotten himself into this time? Clearing the warehouse, he saw his friend, pinned by a headless Kraang-droid but otherwise, seemingly unharmed. Annoyed at the unnecessary spike of fear that Casey's cry had induced, he stomped over in a very un-ninja-like fashion, ripping the robot off his comrade.

Freed, Casey slid to the ground. The droid was empty, so there shouldn't have been any danger.

"Casey? You ok?"

Casey didn't answer. Concerned, he knelt down and grabbed a handful of hoody to tilt his friend's head back as he lifted the mask with his other hand.

"What the…?"

He jerked back so hard, he fell on his shell, dropping Casey back against the trailer. The starburst shape of Casey's pupils had been disturbingly familiar.

Casey groaned and rubbed his head. Clamping his jaw shut and refusing to be afraid, he got up and yanked his friend's head back again. Eyes widened in shock for a moment before narrowing. Casey landed a solid right hook on the underside of his jaw.

"Back off already."

Raph smiled as he rubbed his chin and let out a relieved breath. Normal, round pupils. It was just the dim light and his imagination. He'd totally pulled a Mikey for a moment there.

"Then get up already."

Giving Casey some time to get back on his feet, Raph strode around back and opened the rear door, less than pleased to find a crate of mutagen, leaking all over the floor among all the other weird, metal Kraang-junk. Don would want to decontaminate this before they ended up with more random mutants running the streets. Time to call it in.

As he pulled out his T-phone, he failed to notice Casey approaching from behind, pupils sharp and pointed.

* * *

"Watch it!" Donnie barely ducked out of the way of Mikey's chucks as he burst out of the shellraiser door, before Leo had even brought it to a complete stop.

Mikey bounced on the balls of his feet looking around excitedly. "But Raph never asks for help. I can poke him about it for weeks."

Donnie sighed as he climbed out of the refurbished subway car. "He didn't ask for help. He wanted me to 'clean up some science crap' that the Kraang left." Don used his fingers to create air quotes as he spoke. "You guys just wouldn't let me go on my own."

"No one should be topside by themselves." Leo spoke as he climbed out of the shellraiser. "Where's Raph and Casey?"

"Yo." They all followed the sound of Casey's voice over to the back of the nearby big rig.

Leo's eyes darted around. "Where's Raph?"

Casey shrugged. "He got bored and went for a run, leaving me to guard all the stupid Kraang-junk."

"He what?" Donnie flinched away as volume of Leo's voice risked alerting people in New Jersey.

Mikey smothered a laugh. "So much for no one going topside alone."

Donnie edged away from Leo on the off chance he actually might explode and went to investigate the contents of the semi-truck's trailer. It was mostly filled with disassembled stasis tubes, which he'd seen the Kraang use to contain mutants before. They seemed so innocuous now, but he remembered seeing countless others trapped within their force fields, friend and foe alike, and couldn't help but feel aversion where there was normally buoyant curiosity.

Then his eyes landed on the crate. The crate leaking mutagen all over the floor. Fantastic. He needed to take care of this now or they'd have a horde of new surprises awaiting them in the near future.

Fortunately, he'd come prepared, anticipating a wide span of possibilities. Not that anyone ever noticed or cared. Except when things went wrong. Then they all noticed and cared a lot.

He hesitated, reluctant to go back out into the storm of Leo's wrath. Even in here, he could hear Leo ranting to no one in particular about Raph's thoughtless irresponsibility. It was looking like the next week would be best spent hiding in his lab.

Bracing himself to head back to the shellraiser, he turned and nearly collided with Mikey who was on the verge of buckling under the weight of his toolbox.

Mikey grinned sheepishly. "Sorry, D. Just thought you might want your…thingies."

He couldn't help laughing as he guided Mikey into setting the large kit on the floor. Perhaps there was such a thing as being too prepared.

"Thanks." Maybe he didn't go as unnoticed as he thought.

"Yeah, anything to get away from Leo. He's so mad that he's turning as red as Raph's mask."

Or not. Oh well.

"Be careful not to step in any of the mutagen."

"Yes sir!" He ignored Mikey's mock salute and flipped open the metal box, rummaging for a thick plastic jar and his eye dropper.

A few well-placed applications of the solution quickly turned all the mutagen puddles into nonreactive, frozen solids. It might not have been the retromutagen he'd been seeking at the time of it creation, but it had ultimately proved very useful, though he flinched slightly at the thought of Timothy. He wouldn't be able to fulfill that promise until he found a counter-agent to the freezing chemical, which had been proving more difficult than he ever could have anticipated.

"Mikey, hold this."

His curious little brother, immediately abandoned the cheerful tune he'd been humming and bounded over to grip the steel crate that Donnie had tilted back.

"Dude, are you fixing Kraang tech with duct tape?"

He tore off a strip and began using it to seal up the damaged seam. "While you would not technically be inaccurate in describing this as Kraang tech…"

"D, you've lost me."

"It's a box, Mikey. Just a box."

"Aww, that's kind of boring."

A few more pieces and the hole was sealed up tight. Mikey helped him gather the frozen shards of inert mutagen and toss them in the crate. With a count of three they each lifted an end and staggered towards the door. Instead of the anticipated assistance in getting the crate down, Leo was busy pacing furiously as Casey watched.

Donnie sighed audibly, attracting both their attention. "A little help here. And why don't you just call and yell at him directly?"

Casey came forward to ease the crate down and help Mikey get it to the shellraiser. Leo just raised his T-phone and tapped Raph's speed dial. Before raising a second ringing T-phone in his other hand.

"Oh." No wonder Leo was pissed. They couldn't even track Raph now. While Leo was still wrapped up in his anger, Don could feel a few tendrils of unease starting to creep up his shell. Yes, Raph was impulsive and sometimes reckless, but this level of irresponsibility was unusual, even for him.

Not wanting to give voice to his concerns, he tried for reassuring. "We should get going. He might already be home."

"He'd better be." Leo's voice was icy as he stalked back to the shellraiser.

* * *

Donnie leaned into the crate with a dust pan and hand broom, when he heard the lab door open behind him. He jerked upright, cracking his head on the partially opened crate lid and dropping all the deactivated chunks of mutagen back into the box.

"Oww!"

Who was it? After helping him unload the crate, he was sure that Mikey had retreated into a world of video games and Casey had gone home. After all, April had turned in early tonight because they were supposed to have a big test in school tomorrow and she'd wanted to be that well rested. He couldn't be that cavalier about his grades if he wanted to stay on the hockey team.

Leo should be busy glaring at the turnstiles, waiting for Raph to come home, so that he could assure himself that he was ok before tearing him a new one. And Sensei should be asleep, so…

Rubbing his head, he shoved aside the pain and irritation to climb to his feet and investigate. To his surprise, Casey was wandering his lab, inspecting the different areas of his equipment and projects, currently poking around his chemistry cabinet.

In a moment of blinding terror for his carefully gathered and/or created collection, he rushed over to close the doors before the meathead could break anything. "What are you doing?"

Casey shrugged listlessly. He'd been unusually quiet on the drive back too. Normally he would have been running his mouth in competition with Mikey. Something was wrong.

Don angled his head to peer into his friend's face, now clear of battle makeup, and backed up with a startled gasp. Casey's pupils had looked decidedly Kraangy.

Casey jerked his head up, glaring at him, eyes now normal. Had he imagined it?

"What?"

Donnie shook his head. "Nothing, I guess. Why are you still here?"

Casey looked away and kicked at some imaginary rubble on the floor. "Not that I think I need it, but I was wondering if maybe you could hook me up with some kind of tech suit or robotic exo-skeleton or something. Because how cool would super-soldier Casey Jones be, you know?"

Donnie compressed his lips into a hard line and rubbed his temples. Of course it would be a battle-upgrade request. And now that it had been mentioned his mind was already enumerating the possible ways it could be done and what materials it would require. But he refused to let on. Casey would have to work a little harder than that.

He turned away to resume work on the mutagen crate. "I'll consider it, but right now I'm kind of busy. So if you could…"

He froze as Casey depressed a pressure point at the base of his neck, his mind flashing back to earlier in the week, when Master Splinter had used the exact same move to halt one of Mikey's victory dances during training. Casey had fallen over laughing, but Don had never imagined that the thick vigilante was capable of picking up the move. Except he was now just as paralyzed as Mikey had been then.

Why?

The last thing his mind registered was the sensation of a chloroform scented rag, covering his mouth and nostrils.

* * *

Leo paced angrily back and forth through the pit, thankful that Sensei was already asleep and he had some time to wait for Raph to get home before admitting to his father that he'd lost his brother.

Beneath the seething fury was a deep-seated worry, gnawing at his guts. For all his bluster and defiance, Raph cared about them too much to flake like this. When he took off, he did so with reason. Ditching like tonight was simply not something he did. But the anger was easier. It assumed Raph was safe and on his way home at some point.

He turned at the sound of Casey exiting Donnie's lab. "I thought you went home?"

Casey shrugged as he made his way towards the turnstiles. "Just putting in a request with D, but he's busy doing something with the partywagon."

What?

He stalked off towards the lab, failing to notice that Casey had turned the wrong way down the subway tracks. The way back towards the garage door.

Leo stopped in front of the door, ready to pound his fist against it, when a thought occurred to him. Maybe Don was staying up late, working on something that could wait until tomorrow because he couldn't sleep until Raph was home. Leo sure wouldn't be getting any rest while his brother was out there. Even Mikey had been prepared to stay up and play video games until Leo's pacing had driven him to his room.

With a sigh, he lowered his fist and turned away. He'd barely made it halfway across the lair when he heard the party wagon's engine roar to life and fade away.

Really? Now he had two brothers to worry about.

* * *

Leo perched on the fire escape just outside of Casey's apartment. Unfortunately, it connected to the living room instead of Casey's bedroom so he was reduced to ledge balancing to reach the window he needed. Using his shuko spikes, he latched onto the wall with one hand, while tapping gently on the glass with the other.

A moan emanated from within. "Raph? Dude, it's three in the morning. I know Leo must have chewed out your shell, but couldn't this wait?"

Clad only in pajama bottoms, Casey staggered blearily to the window, eyes widening when he saw who was waiting there. "Oh, hey Leo, um…"

"I take it you haven't seen Raph?"

Casey frowned. "He hasn't gone home yet?"

Leo shook his head. "No. I went out looking for him, but I've run out of likely places to search."

He'd been running the city for hours without success and had maxed out all his brother's favorite hang outs. At least the ones he was aware of.

It didn't help that Donnie hadn't come home yet with the van. When the genius finally returned, Leo intended to insist on being taught how to use the T-phone tracking system. He probably should have known it before now anyway. His mind would be more at ease if Don hadn't turned his phone off before abruptly leaving. Raph wasn't the only one getting a lecture later.

But first Raph. He'd been missing longer and at least Donnie had the protection of the van.

As much as it galled him to admit it, he needed help. "Do you have any suggestions on where to look?"

Casey, having shaken off his sleepiness, thought for a moment. "We did set up a few bolt holes around the city, just in case things go badly. Not that we'd ever need them because we're awesome, but…"

"Show them to me, starting with the nearest one."

Casey sighed and stretched. "Fine. Give me a minute to throw some clothes on."

* * *

The first emergency hideout was the basement of a foreclosed apartment building in the projects that eerily reminded Leo of a nineteenth century tenement. It looked like it should have been condemned.

He swept silently down the steps, eyes quickly adjusting to the darkness. It was a sparse, cement room with a single, bare bulb dangling from the ceiling with a pull chain. There was an old mattress in the corner with a few crates, containing nonperishable food, bottled water and first aid supplies next to it. Austere, yet functional. But there was no Raph.

He started to turn and leave, when a dizzy spell hit him. Double vision threw him further off balance. He could smell it now. The chemical scent was subtle, blending with the decades of mildew and must that all but blinded his sense of smell.

A trap? They needed to get out of here now. He could purge the poison from himself with the healing hands technique once back in fresh air. Willing his body to cooperate, he forced himself to complete the turn back towards the door, just in time to see Casey, wearing one of Don's Dimension X breathers, launching a hockey puck straight towards his face.

He might have been able to dodge it, if he hadn't frozen at the sight of Casey's very Kraang-like eyes.

* * *

Mikey lay in bed, flipping through his comics without really looking at them. Leo's agitation had made him too edgy to hang out in the pit, but he sure couldn't sleep. Something was wrong. He could feel it. He just didn't know what it was. Raph running off wasn't uncommon, but this seemed different, though he couldn't put his finger on why.

His unseeing, comic trance was broken by Leo's grunt of frustration, echoing loudly in the otherwise silent lair. He'd only known his brother was pacing by assumption, unable to hear his silent footfalls.

Rolling out of bed, Mikey peeked through the edge of his door to catch Leo darting out the turnstiles. Probably going out looking for Raph. Why didn't Leo take him too? What about Leo's rule about not going topside alone? Did he take Donnie?

He crept out of his room and confirmed his suspicions when he didn't find Don in his bed or lab. They'd left without him. Dejected, he plopped down on the couch and stared blankly at the television, mindlessly channel surfing. Tired as he was, there would be no sleep until his brothers came home. His brothers who evidently didn't need his help.

* * *

Mikey was on the third movie in a marathon about a boxer named Stoney, when his phone rang. Too eager, he lost his grip on it as he pulled it out of his belt and juggled it in the air before having to dive to catch it, sliding across the pit floor on his chest.

"Bros, is that you?" He'd been too excited to check who it was, but he hoped it was one of his missing brothers.

"Sorry Mikey."

"Casey?" He sat up frowning, wondering why Casey would still be awake.

"I texted you and address that Leo needs us to stake out. Get here as fast as you can."

Mikey rubbed is head in confusion. "But Leo said not to go topside alone."

"You'll be with me, so you won't be alone."

"Oh, okay." He supposed that made sense.

"Hurry up. Leo says Raph needs us."

Elated that his brothers needed him, Mikey turned off the TV and darted out of the lair, remembering to check the address only when he'd reached the surface and realized that he had no clue where he was going.

* * *

Mikey landed lightly on the rooftop with an unnecessarily elaborate flip and plopped down noisily next to Casey on the roof ledge. "What up?"

Casey glanced up at him and smiled. "I reheated some left overs in case you were hungry."

Mikey's mouth watered at the smell of pizza gyoza wafting out to of the doggie bag, reaching in to stuff a handful in his face. "Wha aw we doon hew?"

Casey stared uncomprehendingly at him.

He swallowed and tried again. "What are we doing here?"

"Oh. Tiger Claw got Raph and Leo found out that there bringing him here. When they get here we jump in, pound some Foot and take back what's ours."

Mikey grinned widely, glad to have a plan to get on board with. Though he hoped Raph was alright. Tiger Claw wasn't exactly gentle and it wasn't in his brother's nature to get caught without one shell of a fight. "Where the others?"

Casey pointed down at the partywagon in the alley below. "Oh, okay."

Still, something didn't seem right. Why hadn't Leo called him directly? He should have, shouldn't he? It was getting hard to think. Harder than usual. And his body was now feeling oddly heavy. He wobbled and leaned against Casey for support. "I don't feel so good."

Casey smirked. "Donnie managed to synthesize some pretty powerful sedatives."

Mikey blinked in confusion, though his eyelids were so heavy, it was becoming hard to move them. They just wanted to droop shut. Casey shifted, allowing him to fall back onto his shell. He didn't have the energy to catch himself or even try getting up. Man, he was only ever this tired when he was starving. But he'd just eaten the…

Casey stood, smirking over him as he held the take out bag. The last thing he saw before losing the fight to keep his uncooperative eyes open where Casey's pointy, star-shaped pupils.

* * *

April jerked awake, willing the nightmare away. It was awful. All her friends. Her family. She expected the disquiet to fade, now that she was awake, but it was only growing worse. Something was wrong. She was sure of it. The intuitive sense, she long ago learned not to ignore was practically screaming at her.

Quickly dressing, she pulled out her T-phone and dialed Don. Phone off. She systematically went through the others with no response, balking only at calling Casey when her danger sense spiked.

Not without recourse, she used her T-phone to activate Donnie's tracking system. As long as the phones weren't completely destroyed, it should be able to locate them. All the signals were clustered at one warehouse down by the docks. She needed to get there fast.

* * *

After paying the cabbie, she snuck quietly up to the warehouse, creeping in through the large open door and concealing herself behind a stack of crates. When she poked her head around, she had to cover her mouth to keep from gasping out loud.

There was a row of cylindrical, metal stasis tubes that she'd seen off and on in various Kraang strongholds. Inside the force fields were a panicked, singed-looking Kraang and the unconscious bodies of her friends. Most disturbing of all though was Casey, puttering around a table full of creepy looking, sci-fi, medical tools and several canisters of mutagen.

Taking a large needle and syringe, he strode over the Kraang's enclosure and it squealed with the fruitless effort of backing away from him. With a few button presses the Kraang's force field fell and it made a bid for freedom, only to be pinned down with a violent swing of Casey's bat, freshly drawn from his weapon satchel.

She cringed away from its piercing shrieks as he jabbed the needle in and extracted some purple fluid. Too much. There was no way the Kraang was surviving the loss of that much.

Filled with an unexpected wave of pity for her mortal adversary as it was left to expire on the floor, she watched Casey head back to the table, stopping only to press a button on Raph's prison as he went. Raph, who had been beginning to stir was hit was an electric jolt and let out a strangled yelp before falling still once more.

At the table, Casey was injecting the purple fluid into an open canister of mutagen. What was he doing? As the two substances mixed, he turned back to the turtles, eyeing them consideringly as if…choosing. He was going to use the mutagen on them.

No!

She flung her tessen at him while diving and rolling behind a different pile of crates. He leaned back, arching just out of the way of her weapon's attack arc and swatting it down with his bat.

Flipping his skates on, he scanned the room. "I know you're out there, Red."

She didn't respond, pressing her back against the crates, waiting as he slowly explored the room, seeking her. He neared her stack and she spun around the corner, plowing her heel into his chest and sending him into a sprawling backwards roll.

"Why are you doing this, Casey?"

Using his skates to skid to a halt after completing the somersault, he looked up at her and she gasped. His eyes. Kraang eyes. What had happened to him?

"I was going to wait until the guys and I turned Splinter before dealing with you, but you've pushed the time table forward."

She circled him warily. "Deal with me?"

"I would have loved for you to join us, but with your immunity, you're lost to us. Donnie will understand after I change him."

Casey skated forward, swinging his bat at her, but she ducked, rolling under it and sweeping up her tessen behind him.

He grinned as he turned. "You really think you can win this?"

Her eyes narrowed. "I'm more formidable than you think."

"But you really gonna go all out against me?"

She hesitated. Would she? Could she? If Casey was still in there somewhere… She had to know for sure or he was right. She'd hold back and he'd win.

Concentrating as the circled once more, she could feel brief traces him underneath the layer of twisted Kraang that drifted over the surface of his mind. Kraang? She had one weapon that it hadn't considered.

Drawing his hockey stick with his free hand, he started towards her once more. "Goongala!"

With a scream, she pushed all her fear, pain and grief into one powerful mental blast, feeling the Kraang consciousness shatter under her assault. Casey dropped like a rock and she smiled triumphantly over him for a moment before pitching forward unconscious.

* * *

Casey groaned, his head splitting, wanting to punch in the face of whoever was shining that light in his eyes. His eyes fluttered open, despite the light.

"Knock it off Donnie." He struggled to sit up, finding himself bound to the table in Don's lab. "Guys?"

Donnie put the pen light away. "He's in the clear."

He looked around to see April, the other turtles and Master Splinter surrounding his table. Raph snickered at his involuntary flinch at the sight of the giant rat, he still had yet to completely accustom himself to.

Leo leaned in. "What do you remember?"

He moaned and leaned his head back down. What was the last thing that happened to him? The Kraang had him pinned…and the mutagen…

"The warehouse…fighting Kraang…with Raph…"

Mikey rested his head on his hand, elbow propping him up on the table next to Casey, waving about a half-eaten slice of pizza with his free hand. "Dude, that was like three days ago."

Three days!

Donnie scoffed. "You're just lucky, we had all that mutagen to refine into retromutagen or who knows how long it would have taken to fix you."

Fix him?

"What did I turn into?"

April placed a reassuring hand on his shoulder. "Don't worry about it. Everything is fine now."


End file.
